To obtain the ultra-low interfacial tension foam flooding system for the real reservoir condition of high-temperature and high-salinity, foam properties and dynamic interfacial tension had been performed by Ross-miles test and spin drop tension meter respectively. Ten types of surfactants were screened by foamability, stability and interfacial tension (IFT) at 85°C, high-salinity with 800 mg/L divalent cations and 30000 mg/L total mineralization. The AOS, AESO and 20YB were selected to compose further anion-nonionic mixture system. Due to AOS had excellent foam properties, AESO could achieve low interfacial tension and 20YB could improve the film quality. Through series complex study, the ultra-low interfacial tension (10-4 mN/m order of magnitude) foam system was obtained with the composition of 0.15% wt AOS+0.15% wt AESO+0.11%~0.012% wt 20YB for high-temperature and high-salinity, which V foam was 240-235 mL and t 0.5 was 180-190 min. In addition, the synergistic effect of these surfactants had been described.